1. Technical Field
The present disclosure relates to a positive-electrode active material for a non-aqueous electrolyte secondary battery and a non-aqueous electrolyte secondary battery including the positive-electrode active material.
2. Description of the Related Art
A lithium-containing transition metal oxide that has been studied as one of next-generation positive-electrode active materials is produced by ion exchange of a sodium-containing transition metal oxide, belongs to the space group P63mc, and has the O2 structure. Such a lithium-containing transition metal oxide used as a positive-electrode active material is expected to have higher structural stability and capacity than lithium cobalt oxide (LiCoO2), which is practically used, belongs to the space group R-3m, and has the O3 structure. Japanese Unexamined Patent Application Publication No. 2012-204281 discloses a lithium-containing transition metal oxide that has the O2 structure and contains Li in the transition metal layer.
However, the positive-electrode active material disclosed in Japanese Unexamined Patent Application Publication No. 2012-204281 requires a high activation voltage for initial charging and has poor battery performance.